package ch8.MatGraph;

import java.lang.*;
import java.util.*;

public class BFS {
    static final int MAXV = 100;            //表示最多顶点个数
    static int[] visited = new int[MAXV];   //访问标志数组

    public static void BFS(MatGraphClass g, int v) {   //邻接矩阵g中从顶点v出发的广度优先遍历
        Queue<Integer> qu = new LinkedList<Integer>();  //定义一个队列
        System.out.print(v + " ");  //访问顶点v
        visited[v] = 1;             //置已访问标记
        qu.offer(v);                //v进队
        while (!qu.isEmpty()) {     //队列不空循环
            v = qu.poll();  //出队顶点v
            for (int w = 0; w < g.n; w++) {
                if (g.edges[v][w] != 0 && g.edges[v][w] != g.INF) {   //存在边<v,w)
                    if (visited[w] == 0) {          //若v的邻接点w未访问
                        System.out.print(w + " ");  //访问顶点w
                        visited[w] = 1; //置已访问标记
                        qu.offer(w);    //w进队
                    }
                }
            }
        }
    }

    public static void main(String[] args) {
        MatGraphClass g = new MatGraphClass();
        int n = 6, e = 7;
        int[][] a = {{0, 1, 1, 0, 0, 0},
                     {0, 0, 0, 0, 0, 1},
                     {0, 0, 0, 1, 1, 1},
                     {0, 0, 0, 0, 0, 0},
                     {0, 0, 0, 1, 0, 0},
                     {0, 0, 0, 0, 0, 0}
        };
        g.CreateMatGraph(a, n, e);
        System.out.println("图g");
        g.DispMatGraph();

        System.out.print("DFS: ");
        Arrays.fill(visited, 0);    //初始化所有元素为0
        BFS(g, 0);
        System.out.println();
    }
}
